1. Field of the Invention
This invention relates to sonobuoy deployment apparatus and more particularly to preselected depth deployment of the sonobuoy hydrophone.
2. Brief Statement of the Prior Art
Sonobuoys are devices adapted to be dropped by parachute from an aircraft, are equipped with an hydrophone for detecting underwater sounds in either an active or passive manner and transducing the sounds to electrical signals and have an automatic radio transmitter for transmitting the signals to air and surface craft. A wound cable packed in the sonobuoy connects the surface transmitter and the underwater hydrophone and is automatically payed out after the sonobuoy enters the water. The cable length determines the underwater depth of the hydrophone. Different cable lengths are desired for different water bottom depths and other conditions.
One manner of obtaining different depths is simply to package a wound cable having a length desired for a particular application. Each sonobuoy thus is restricted to only one hydrophone depth. A sonobuoy capable of multiple hydrophone deployment depths substantially increases the sonobuoy versatility and reduces sonobuoy logistic requirements and this invention is directed towards this purpose.